Dynamics & Space Flashcards
How is the distance travelled by an object measured?
The distance travelled is measured along the path followed by the object
How do you measure the displacement of an object?
The displacement is measured in a Straight Line from it’s start point to it’s finish point
What is a scalar quantity?
A Scalar has size only. e.g Distance,Speed ,Mas,energy, density
What is a vector quantity?
A vector has size and direction. e.g Displacement,Velocity, weight, acceleration , force
What is the relationship between Distance,speed and time?
D= s x t
D= distance
s= speed
t=time
What is the relationship between Displacement and velocity?
D = V x t D = displacement v= velocity t= time
How are vectors in a straight line added?
Using Normal Arithmetic
what are the two ways to add vectors at a right angle?
By scale drawing or by calculation using pythagoras
How are vectors added in a scale drawing?
Nose to Tail
what do you use to find the bearing of a vector?
SoH CaH ToA
how do you measure a bearing?
In a circle from North.
How do you write a bearing?
21 degrees = 021
210 degrees = 210
What three things of an object can forces change?
Shape
Speed
Direction
What is weight?
Weight is the gravitational force acting on an object.
Can weight change?
Yes. The weight of an object can and does change as it moves.
What is the relationship between mass,weight and gravitational field strength?
W=mg
W= weight
m= mass
g= gravitational field strength
What is the relationship between gravitational field strength and acceleration due to gravity? (when frictional forces are ignored)
Gravitational field strength is numerically equal to acceleration due to gravity when frictional forces can be ignored.
What is Friction?
Friction is a force that opposes motion
When do we wish to increase the frictional force of two objects?
When a car is going round a corner,the force of friction between the tyres and the road helps to keep the car on the road
When do we wish to decrease the frictional force acting on two objects?
skier in a downhill race wants to get to the finish line as quickly as possible.